Lifting jack



May 23', 1950 A. A. BERG LIFTING JACK Filed March 14, 194s 2@ C729/Patented May 23, 1950 UNITED STATES PATENT OFFICE `asos'szlt'r y YLIFTrNQ JACKy Arthur A Bfei' einer@ ,m Application March 14, 1948,Serial No. 654,382 A1claim,...(enfasi- 126) This invention relates to alifting jack especially adapted for use with automobiles and motortrucks in connection with-the repair of tires and for making otheradjustments.

One object of the invention is to provide a simple and economicalstructure adapted for a jack of the parallelogram type having. anadjusting screw and provided with stabilizing links connected toextensions of the operating links of the jack and adapted to hold thelower and upper platform or supporting members in vertical alignment, orsubstantially so.

Other objects and advantages of the invention will appear from thefollowing description taken in connection with the drawings, in which:

Fig. l is a side elevation of Aa jackA embodying this invention, showingthe parts Vpartially extended in lifting position;

Fig.- 2'is a similar side elevation showing the parts fully collapsed atthe lower limit;

Fig. 3 is an end elevation` of the structure as it appears in theposition shown in Fig. 2;

Fig. 4 is -a detail view of an operating handle.

In providing a jack for use with automobiles or motor trucks, it is notonly important to provide for adequate extension of the structure butalso to insure that it can be collapsed to a position at which it can beeasily installed under the axle of a vehicle of modern design in whichrelatively small wheels are employed and. in which the tires constitutesuch a large proportion of the Wheel diameter that when Vthe tire iscollapsed, as in the event of a blowout or puncture, the axle is broughtquite close to the road surface; Although the parallelogram system oflinks employed in the jack of the present invention permits of a fairlycompact collapsed position of the structure, the invention includes thespecial formation and design of the link members by which a minimumvertical height is assured when the parts are adjusted at their lowerlimit.

As shown inthe drawings, the jack includes a support or base I0 havingupright flanges I2. spaced apart laterally and providing support for thepivots I4, I4 V.by which two pairs of ,links I6, I6 and I1, |'I`areconnected to the base. Said links extend obliquelyY upward and crosseach other, as shown in Fig. 1, and near their upper vus 20,"and pivots3434 serve to connect the ends of. thek links 3| witl1rtliersevextensions ofthe links 21...

ends the links I6 are pivoted at I5 to a block I8 which is, journalledupon an operating screw I9.V The upper ends of the links are pivotedwtoa block 2li having threads by which it engages the screw I9 forlongitudinal adjustment thereon. The screw I9 is provided with ra head2| which is preferably of spherical formand includes a cross bar 212forV connection .with a suitable op-, erating crank, not shown.. 1.

Extending upwardly from the block I8 ls a pair of links 23', 23,pivotally connected at 24 to the flanges 25 of the upperv platform 3|).`Another pair of links 2l, 21 are pivoted at 28 to the threaded block2|I'andy theirV oppositeends are pivoted att-29, 29 tothe flanges25,0f`the platform 3U. -r AThis arrangement of links |6,' I'I, 23, and2l constitutes the parallelogram system which oper.- ates to raise andlower the platform 30 when the screw I9 is rotated. Preferably, asuitable anti-friction washer or bearing 26 is interposed betweenxtheshoulder of the head 2| and the shoulder of the block I8, said blockforming a journal bearing for the shank of the screw-,I9 in which it isrotatedfor adjusting the height 0f the'platform 30.

Tostabilize thek structure, however, so that the platform 30 shallremain always. directly over the base l0, and also parallel thereto, theAdevice includes two pairs yof stabilizing links 3|, 3| and 32, 32. Thelinks 3|,` 3| are connected respectively to the lifting links I6 bypivots 33 `disposed adjacent the pivotsfld by which the links I6, areattached tothe base I8. Attheir opposite. ends the stabilizing links 3|are connected to portions of the vlinks 27, 2l "which extend beyondvtheir pivotal engagementatZB with the threaded block,

Similarly, thelinks 32, 32 are connected respectively to the links 21,2'|by means of pivotsY 35, 35neartheir pivots 29, 29 which connect saidylinks l2'I to the upperplatform 30. V. The opposite ends of the links32, 32J areV connectedV by pivots 36 4to extensions of `thelinks I6, I6beyond their pivotal connections at I5 to the block I8shanko'fthescrewIS.V v i' u It will be seen from Fig. 1 that at vanyposition of. its upward extension, the provision of the stabilizinglinks 3| 'and 32 prevents the platform 30 from tilting out of itsparallel position with respect to the supporting base so ,that as thescrew I9 is rotated and throughout the range of vertical movement ofthe.- platform 30, the platformV will remain44 substantially :above-fthe 'sup- ,port'IlI and:parallel-to1t; 'i y' r onthev Fig. 3 indicates aconvenient manufacturing design for the jack in which the base I isprovided with a channel or U-shaped member Illa which includes theupstanding flanges I2, I2 in which the pivots I4, I4 are secured.Similarly, the platform member 3U is provided with a channel shapedmember 30a having the integral flanges 25, 25 in which the pivots 29 and24 are secured for anchoring the links 23 and 2'I. The link members 23,"23 are secured against `the outer faces ofthe anges 25,25 and the linkmembers 2l', 21 overlap the members 23, 23 as inf dicated in Figs. l and3, being spaced from the' anges 25, 25 by suitable washers 38, 38..`.Thestabilizing links 32, 32 are disposed outside the other links of theassembly as indicatedn"liigzI 3. Similarly, the lower links t, EFI[,-andfIj-are arranged in overlapped relation as shown in Fig. 3.

When the screw I9 isrrotated in one direction, the lthreadedi block' 2Dlis "caused 'to 'approach'.the journal fbflook i 8, 'forcing `'the linksJ6 .land Irl :to swing `upwardlyfand Lalso forcing Zthe lower fends ofithe links 23 land/221 4to approachI soi as `to -litt the iplatform --30.in a ..well-'understood manner. Asfthe platform rises,^.itiis.preventedfrom'A tilting by meansof 4the stabilizing linksl I and 232 and theplatform .therefore is maintained in parallel relation to the base I0.`Sntvi'ew-fotlthesubstantially:=symmetr-i'cal 1 arrangement J of :thelin-ks .I 6, H323, and :21,:the1platform-3II is.maintained in aAposition ssubstantially above the base im throughout its frange! ofverticali movement.

,To `permit :rotative `movement :of the links I5 and l I 'Ifaboutltheiripivots t4, without interference with`-1the.base plate I'foftnestructure;thellower edges and #corners of th'e Llinks I5 --and lI'I-are trimmed at Isa and 11a, thus-permitting said links "I5=andillf-toswing downwardly: to '-afgreater extent ythan 1 would beffpossible :if ftheir -eorners were left squareias atlthe-upp'er 5sidesVofftli'e'links. Similarly, lthe upper fcornersf-Zia Yand 27d of thelinks'fZS: and 321 iaresl-i'esped lto xavoid interferencewilthlthefplatform 'member-'IlI-asthe ack l is coilapsed to its lowerlimit, as shownin Fig. 2.

Thus .-wliile thel pivots f M 24',fandl'28 'aredisposed substantially salong` the 1 center :lines of the i links |26, Ill, '223, fand L21,fsaid links fznay lbe fswung through greaterA angles .them .if theircorner portions wereinotfthus1cut `oif .or roundedandas 1a result :theijack loan be i4collapsed to -a -smaller minimum I height "as iridicatedin fFig. i 2, uwithotit anyiasaoriceofstrength or convenienceoflop'eration.

AxPreferably, the :operating handle for 1 rotating th'erscrewl I9l-isf'made readily detachable ffrom 'the sphericallyformed terminal-portion 2l of :the screw. IA fportionfoflsuohi anv` operating i handlei is shown 1in lig.14--atlill, it being understood v'that one fend ofthe handle may be Zprovided with -a crossbarL or: otherconvenient-means'ifor frotating it. @nel other endihasfsecureditoiit rigidly/,as by'.rivets, a tpairzo'f plates 4I formed at 242 lto fit the curved form.of theihandleitll. LBoth fplates have :arcuate notches 13 :in `Ztl-reirfopposite fends, said notches being dimensioned',tozapproimnatelyitpthe'urvature-of the terminal A2 I sofas .toembraceiit, Vas;showninLJFig. 4. Infthisypositionthe plates :4I will overl-apthe projectingendsiof the cross pinJZZin'the-iterminal 2l `soas to provide a ldrivingengagementlforrotating the screw IES. Both '.plates-have in-iturned.terminal flanges -1'4-4 which aire spaced-:apathy :something .less rthan theifull: diameter of: thefpin522 soas :to retainnthe handle indriving positiononiftheterminal 72'I.

The projecting portions of the pin 22 are each flattened at one side asshown at 22a so that when the handle is swung to extend at right anglesto the screw i9, as seen in dotted outline in Fig. 2, the smallerdimension of the pin 22 will pass between the opposing flanges 44 so asto permit disconnection of the handle when the jack is out of service.

While there is shown anddescribedherein certain sstructure illustratinjVanfd embodying the invention, it will be understood that various.changes and modifications will occur to those 'skilled in the art andmay be made without departing from the spirit of the invention, and itis the intention to cover within the scope of the 'appended claims allsuch alterations and all equivalents "Whichzmay be substituted for thefeatures Vwhich are herein disclosed. For exampie; -if desired, thescrew I9 may be formed with right and left llar-id threads, and both theblocks :f8 and'. 2.0 i mayb'ethreaded ito 1 respectively engage ftheright :antik-left ihand threads fof lthe member IIS so :that iboth"blocks v--vi'ill itravel on said member when litlis:rotated.ltlalso'may be understood that :the :provision of itlie -channel membersima and-39a his mer'elyfa preferred -ex pedient itofprov-idemeans'forettachingthe-links to tthe :base :and sto fthe platform V:andthat Jconnecting lugs ffor the pivots 1215224, and 29 #maybesotherwi-selsecured"-toithebase andato-:the plat-- formifdesired'.

I claim: jack :comprising a ibase, ftwo llower pairs Aof liftingilinkspivoterl alt ftheir'ower eII'ds-'to s/id base, the .linksf'ofi one.fpairfoross'ing "those Iof the.

other pair, a escrow, blocks :'nrounted "en fthe screw and 'pivotally*connected to said pairs of liftingI link-s; respectivelyfv achilinkrifL one=pai-r fof said lower links including an-xterideifl `rinortionprojecting? beyond ;th'e:point 6f=pivot/al:conneetion of :said :links'-.fwithfrone fof' saidi blocks, 4two uppertofsaidlblccksvrespectivelyyafplatform; said upper links being `pivotedat itheir rapper lends to said platform, one pair of saidf-up'perilinksl'crossing tnefotherf pairreach;linkfofneipairl o'f said upperlinks including an #extended portion project/'ing beyond 'the -peint :ofi pivotal fzoimection of #said links with. the otherioffsaidblook's,ar-idea 'pair-idf stabilizing .members seach fpivoted aait one 2end 6tothe fextended vpo'rtionl offo'nefof. said Lliftixrg f links,respectively, 'at a point beyond itl-1e pifvotab eo'nnectionxotsaid:linknto ith'erblock, 'and pivoted at the retirer .fend '.to .another'l'itt'irig ilink Lat -fa Jpo'int intermediate Lthe :pivoteii ends #of'said linkarid adjacentto therend: therefisvlifichi'isi remote from the.fscrew, the ceccentrincity of fthe pivotal A nectionsfbetweenath'erespective stabilizingfmem bersiandsthe liftingflinksitolwhic'hftlieyfareconnecte'd fleeing4 equalzand opposite avi-th respectftothe faxis of the screw fand lwith respect :to ltne axis of movement fof:the @platform :with 'respectv

